This description relates to an information update method for access points (hereinafter referred to as APs) adapted to update information of a plurality of APs stored in a hand-held terminal, and a handoff support apparatus and a method using the same for supporting handoff of the hand-held terminal using the updated information of the APs.
A wireless personal area network (WPAN) is a communication network for enabling a small number of hand-held terminals to perform communication mutually using a wireless channel at a short distance within about 10 meters. A key concept in WPAN technology has been known as ultra wide band (UWB) communication, Bluetooth, wireless local area network (WLAN), Zigbee and infrared data association (IrDA).
The WPAN has been widely used for substituting the wireless communication for the wire communication of the terminals that are located within the short distance. Accordingly, the scope of application of the WPAN is expected to be broadened.
Recently, the Bluetooth spotlighted as a typical short distance communication technology has been increasingly developed since the Bluetooth standard version 1.0 was announced as an official standard by Bluetooth Special Interest Group (SIG) (Ericsson, Nokia, IBM, Toshiba and Intel). IEEE 802.15 Working Group was formed as an official group for international standards, and has been closely worked together with SIG for the purpose of establishing international standards based on the Bluetooth standard.
The Bluetooth version 1.0 provides a data transfer rate up to 1 Mbps. Considering a header of a packet, an effective data transfer rate is up to 723.2 kbps in one direction, 57.6 kbps in the other direction, and 433.9 kbps in both directions. A transmission distance is within about 10 m in 1 mW transmit power, and the transmit power is prescribed up to 100 mW.
The Bluetooth sets 79 channels each having a bandwidth of 1 MHz in an industrial scientific medical (ISM) frequency band of 2.4000˜2.4835 GHz that can be used by users without licenses, and transmits data while changing channels about 1,600 times per second in a frequency hopping spread spectrum.
The Bluetooth can accurately transmit data in a wireless environment with heavy noises by using the frequency hopping spread spectrum and can avoid frequency interference by transmitting/receiving a predetermined packet and hopping the packet on a frequency of a new channel. Therefore, the Bluetooth can perform the hopping more quickly in the same frequency band over other systems, and can transmit data more stably using a shorter packet.
As the short distance communication technology is mounted to a hand-held terminal such as a mobile communication terminal, the hand-held terminal can receive a predetermined service provided by the AP by way of the hand-held terminal and the AP being interconnected via a short distance communication link. For example, an AP installed at every home and office is provided with a private branch exchange (PBX) system connected to a wire telephone network to allow the hand-held terminal to perform a short distance communication with the AP, by which a user can use the hand-held terminal to provide a telephone conversation service with the wire telephone network or a landline via the AP and the PBX system.
Furthermore, a single administration server is provided with a plurality of APs to form a group, and a hand-held terminal selectively connects with a single AP within the group according to a current position to thereby enable to receive a predetermined service provided by the group.
In case a hand-held terminal is to be connected to an AP, the AP that is connectible via a short distance communication link should be first searched, and authentication procedures with the searched AP should be performed to get an authentication for the connection. In order to get the authentication for the connection, each AP should be provided with an intrinsic address and a personal identification number (PIN) code. At the same time, the hand-held terminal should be pre-stored with the address and the PIN code of the AP.
In order to get awarded with the authentication for the connection, the hand-held terminal first searches for the AP to obtain the address thereof, and transmits to the AP a PIN code corresponding to the obtained address. The AP compares its own PIN code with the PIN code transmitted by the hand-held terminal to authorize the connection if both PIN codes are identical.
The hand-held terminal should be stored with a plurality of AP addresses and PIN codes in order for a single administration server to manage the plurality of APs, and for the hand-held terminal to be selectively connected with the plurality of APs.
The storage of the AP addresses and the PIN codes should be done by manipulation of the hand-held terminal by a user, which consumes much time and causes much inconvenience. As a result, a technique is required for enabling an easy storing of the AP addresses and PIN codes in the hand-held terminal.